The present disclosure relates to a reciprocating compressor that includes a cylinder and a piston, and more particularly, to a reciprocating compressor capable of reducing a frictional area between the cylinder and the piston, thereby allowing the piston to more effectively and efficiently reciprocate within the cylinder. The reciprocating compressor is also capable of facilitating the assembly process involving the cylinder and the piston.
Generally, a reciprocating compressor serves to intake, compress, and discharge a refrigerant as a piston linearly reciprocates within a cylinder. The reciprocating compressor may be classified into a connection type reciprocating compressor or a vibration type reciprocating compressor according to the method employed to drive the piston. In the connection type reciprocating compressor, the piston is connected to a rotating shaft associated with a rotation motor by a connection rod, which causes the piston to reciprocate within the cylinder, thereby compressing the refrigerant. On the other hand, in the vibration type reciprocating compressor, the piston is connected to a mover associated with a reciprocating motor, which vibrates the piston while the piston is reciprocated within the cylinder, thereby compressing the refrigerant. Hereinafter, the term “reciprocating compressor” will refer to the vibration type reciprocating compressor.
A conventional reciprocating compressor comprises a reciprocating motor including an outer stator, an inner stator, and a mover disposed between the two cylindrical stators; a cylinder forcibly inserted into the inner stator which is either fixed to a frame or configured to perform reciprocation together with the mover. The reciprocating compressor also includes a piston coupled to the mover, for compressing a refrigerant while performing a reciprocation within the cylinder; and resonant springs disposed at the front and rear ends of the piston, for inducing piston motion relative to the cylinder. A suction passage, through which refrigerant is drawn in, is formed in the piston, and a suction valve is disposed at the same end of the piston. Also, a discharge valve is disposed at the fore end of the cylinder.
As the piston reciprocates with respect to the cylinder, the reciprocating compressor intakes, compresses and discharges refrigerant. The above process is repeatedly performed. However, with conventional reciprocating compressors, there are significant problems associated with assembly. More specifically, there are a plurality of bearing portions formed on the outer circumferential surface of the piston and oil pickets associated with the inner circumferential surface of the cylinder. During assembly, sliding each of the bearing portions past the oil pockets can be difficult. To minimize the difficulty, the length of the bearing portions can be increased relative to the length of the oil pockets. But this increases the frictional area between the cylinder and the piston. This, in turn, causes the undesirable affect of increasing the frictional loss of the reciprocating compressor.